diff --git a/dargs/dargs.py b/dargs/dargs.py
index 5ea6ad2..4ab2a96 100644
--- a/dargs/dargs.py
+++ b/dargs/dargs.py
@@ -662,6 +662,7 @@ def default(self, obj) -> Dict[str, Union[str, bool, List]]:
                 "name": obj.name,
                 "type": obj.dtype,
                 "optional": obj.optional,
+                "default": obj.default,
                 "alias": obj.alias,
                 "doc": obj.doc,
                 "repeat": obj.repeat,